Abdominal pump treatment increases leukocyte count and flux in thoracic duct lymph

Abstract

Previous studies suggest that rhythmic compression of the abdomen (abdominal lymphatic pump, ALP) enhances immunity and resistance to infectious disease, but direct evidence of this has not been documented. Thus, the hypothesis that ALP increases leukocyte numbers in thoracic duct lymph was tested in five anesthetized, open-chest dogs. The lymph duct was catheterized, lymph flow was measured, and lymph was collected under 1) baseline conditions, 2) during ALP. ALP increased lymph flow from 0.5±0.1 to 2.7±0.3 ml/min and increased leukocytes from 1.7±0.2 × 106 to 6.2±0.4 × 106cells/ml. Relative proportions macrophages, neutrophils, total lymphocytes, T cells, and B cells did not change during ALP. Considering increases in flow and leukocyte counts, ALP enhanced leukocyte flux from 0.75±0.04 × 106to 17 ± 2 × 106cells/min. In summary, ALP significantly increased both thoracic duct lymph flow and leukocyte count, so leukocyte lymphatic flux was markedly enhanced. Enhanced mobilization and lymphatic transport of immune cells during abdominal compression is likely an important mechanism responsible for the enhanced immune responses of patients treated with ALP. (Support: NIH grant U19 AT002023)